<div id="subnav">
    <ul>
        <li><?php echo link_to('View Files',array('controller'=>'admin/files' )
        )?></li>
        <?php if (has_access_to('Files::Modify File Types')) { ?><li><?php echo link_to('Modify File Types',array('controller'=>'admin/files' ,'action'=>'file_types')
        )?></li><?php } ?>
    </ul>
</div>